Noninvasive diagnostic and surgical techniques for congenital heart disease have achieved major advances in the last decade. These changes have generated controversies in the areas of diagnostic test utilization and surgical treatment strategies. Over a three year period, we propose to assess different strategies in diagnostic test usage and surgical treatment for a variety of common pediatric cardiologic problems using decision analysis and, where appropriate, cost-effectiveness analysis. Analysis of diagnostic test decisions will focus on the use of routine preoperative cardiac catheterization in children with 1) d-transposition of the great arteries and intact ventricular septum; 2) atrial septal defect, and 3) coarctation of the aorta. We will also evaluate the use of routine electrocardiogram, chest radiogram, and M-mode echocardiogram in children with history and physical examination suggestive of innocent murmurs. Analyses of surgical treatment decisions will include comparison of the strategies of early primary correction and two-stage correction in infants with 1) tetralogy of Fallot and 2) complete common atrioventricular canal defects. The assumptions underlying these analyses will be based on published literature and, where data are lacking, on judgements of experts. The most uncertain data and subjective judgements will be subjected to sensitivity analysis. Computations will be performed using a computer program already developed for decision analysis. A working group comprised of the PI and consultants to the project will meet on a regular basis to discuss the design and interpretation of the analyses. The proposed project will assess the conditions under which a given diagnostic test or surgical treatment strategy is optimal. Computation of cost-effectiveness ratios will facilitate comparisons with other health procedures and technologies.